1. Field of the Invention
This invention relates generally to reducing heat build-up in an electronic device, and, more particularly, to a structure for directing airflow over an electronic device.
2. Description of the Related Art
Generally, computer systems are comprised of a cabinet or housing that contains a plurality of components or subsystems, such as processors, memory, interfaces to various peripheral devices, a power supply, video systems, audio systems, disk drives, and the like. Each of these components generates some heat, and collectively, the computer system can generate substantial heat. In fact, many computer systems include various devices and systems to help remove excess heat from the cabinet so that the various electronic components located therein will not overheat and fail; or otherwise operate erratically. For example, many computer systems include a fan that operates to improve circulation through the cabinet or housing as a whole.
Further, individual components, such as a microprocessor, may produce substantial local heating. This local heating has been successfully dissipated by a heat sink mounted directly on the individual component. Typically, these heat sinks improve heat dissipation by increasing the effective surface area of the individual components. Some heat sinks include a plurality of fins that extend outward from the components. Thus, air from the fan flows over and between the fins, and cools the individual components.
As computer systems have become more complex and powerful, the individual components located therein have likewise become more powerful, and thus, have a greater density of electronic devices located therein. This increased density generally increases the amount of heat produced by the individual components. Increasing the number and size of the fins located on the heat sinks has generally provided increased cooling. Unfortunately, as the number of fins has increased, airflow provided by the fans has been inadequate to penetrate the now relatively dense fin structure, limiting its ability to cool the component.
Increasing the airflow to a sufficiently high level has proven problematic. Generally, fans are located adjacent an exterior surface of the cabinet, and thus, tend to be relatively remote from at least some of the components in need of cooling. Thus, airflow sufficient to provide the desired level of cooling to relatively remote components requires relatively large and/or high-speed fans. These fans tend to be noisy, consume substantial electrical power, and, because of their large size, consume valuable real estate in the computer system cabinet.
As a consequence, some computer systems have added a small auxiliary fan adjacent the overheating component. These auxiliary fans have provided some relief but they have created additional problems. For example, making the physical and electrical connections to the auxiliary fans has generally been a manual process, which adds to the cost and complexity of constructing the computer system. Moreover, the addition of these manual processes increases the possibility of errors in construction, and thus, reduces the overall reliability of the computer system. Further, with the growing complexity of modern computer systems, more and more individual components require additional cooling capacity. As the number of components that need cooling increases, the problems associated with installing auxiliary fans are compounded. That is, it is generally not cost effective or efficient to install a plurality of auxiliary fans.
In one aspect of the present invention, an apparatus for removing heat from a device mounted on a printed circuit board is provided. The apparatus is comprised of a heatsink coupled to the device and a shroud mounted on the printed circuit board. The shroud extends over the heatsink and has a generally polyhedron configuration with at least two openings positioned substantially opposite one another for directing airflow through the shroud and adjacent the heatsink.
In another aspect of the present invention, a cooling system is provided. The cooling system is comprised of a printed circuit board with at least one heat-generating device mounted on the printed circuit board. At least one heatsink is coupled to the heat-generating device, and a shroud is mounted on the printed circuit board and extends over the heatsink to substantially enclose the heatsink on at least three sides.
In still another aspect of the present invention, an electronic device is provided. The electronic device includes a housing with a fan positioned adjacent the housing and adapted for producing airflow within the housing. A printed circuit board is mounted within the housing, and a heat-producing device is mounted on the printed circuit board. A heatsink is coupled to the heat-producing device, and a shroud is mounted on the printed circuit board and extends over the heatsink to substantially enclose the heatsink on at least three sides.